Meningitis After Tooth Extraction and Sinus Lavage in a Horse

A five-year-old Thoroughbred mare was evaluated because of chronic, malodorous, unilateral nasal discharge, and suspected maxillary cheek tooth root abscess. Skull radiographs revealed bilateral sinusitis suspected secondary to tooth root abscessation of 109 and 210. Following oral extraction of 109, bilateral conchofrontal sinus trephination and lavage; fever, tachycardia, and cervical stiffness developed. A lumbosacral cerebrospinal fluid tap was performed, and a presumptive diagnosis of bacterial meningitis was made. Targeted therapy consisted of antibiotic treatment with penicillin, enrofloxacin, and metronidazole, as well as antiinflammatory treatment with flunixin meglumine, dexamethasone, and dimethyl sulfoxide. Following the resolution of fever, tachycardia, and cervical stiffness, the second abscessed tooth, 210, was extracted. The mare was discharged receiving enrofloxacin. Twelve months later, the mare continued to do well with no residual signs of meningitis. Bacterial meningitis should be regarded as a life-threatening, although rare, the complication of dental or sinus surgery in horses. Early diagnosis and therapy may result in a successful outcome.